The Pentagon said on April 14 that the United States carried out up to 80 air strikes against Islamic State (IS) extremists in Afghanistan during the first three months of 2016 under new rules of engagement.

U.S. Brigadier General Charles Cleveland said the increased focus on IS in Afghanistan has been possible because U.S. forces were given broader authority to target the militants since the start of the year.

Before January, the U.S. military could only attack IS militants in Afghanistan under narrow circumstances, such as the protection of troops.

Cleveland said the air strikes have decreased the capacity of IS in Afghanistan, where fighters loyal to the Islamic State leadership in Syria have been challenging Afghan Taliban in some parts of the country.

Cleveland said up to 80 percent of the air strikes have been in the eastern Afghan province of Nangarhar, where the IS has set up a strong base.

He also said the southern Afghan province of Helmand was not on the verge of falling into the hands of the Taliban, but was a "difficult, contested area."

In February, Afghan forces pulled out of some parts of Helmand Province after months of heavy fighting against Taliban insurgents.